Dear Marmam members, My co-authors and I are pleased to share with you our recent publication on fin whale mitogenomics in Molecular Phylogenetics and Evolution. Cabrera, A. A., J. P. A. Hoekendijk, A. Aguilar, S. G. Barco, S. Berrow, D. Bloch, A. Borrell, H. A. Cunha, L. Dalla Rosa, C. P. Dias, P. Gauffier, W. Hao, S. Landry, F. Larsen, V. Martín, S. Mizroch, T. Oosting, N. Øien, C. Pampoulie, S. Panigada, R. Prieto, C. Ramp, V. Rivera-Léon, J. Robbins, C. Ryan, E. Schall, R. Sears, M. A. Silva, J. Urbán, F. W. Wenzel, P. J. Palsbøll and M. Bérubé (2019). "Fin whale (Balaenoptera physalus) mitogenomics: A cautionary tale of defining sub-species from mitochondrial sequence monophyly." Molecular Phylogenetics and Evolution 135: 86-97. ABSTRACT The advent of massive parallel sequencing technologies has resulted in an increase of studies based upon complete mitochondrial genome DNA sequences that revisit the taxonomic status within and among species. Spatially distinct monophyly in such mitogenomic genealogies, i.e., the sharing of a recent common ancestor among con-specific samples collected in the same region has been viewed as evidence for subspecies. Several recent studies in cetaceans have employed this criterion to suggest subsequent intraspecific taxonomic revisions. We reason that employing intra-specific, spatially distinct monophyly at non-recombining, clonally inherited genomes is an unsatisfactory criterion for defining subspecies based upon theoretical (genetic drift) and practical (sampling effort) arguments. This point was illustrated by a re-analysis of a global mitogenomic assessment of fin whales, Balaenoptera physalus spp., published by Archer et al. (2013), which proposed to further subdivide the Northern Hemisphere fin whale subspecies, B. p. physalus. The proposed revision was based upon the detection of spatially distinct monophyly among North Atlantic and North Pacific fin whales in a genealogy based upon complete mitochondrial genome DNA sequences. The extended analysis conducted in this study (1676 mitochondrial control region, 162 complete mitochondrial genome DNA sequences and 20 microsatellite loci genotyped in 380 samples) revealed that the apparent monophyly among North Atlantic fin whales reported by Archer et al. (2013) to be due to low sample sizes. In conclusion, defining sub-species from monophyly (i.e., the absence of para- or polyphyly) can lead to erroneous conclusions due to relatively “trivial” aspects, such as sampling. Basic population genetic processes (i.e., genetic drift and migration) also affect the time to the most recent common ancestor and hence the probability that individuals in a sample are monophyletic. The paper is *Open Access* and *freely available online* from the link below: https://doi.org/10.1016/j.ympev.2019.02.003 If you have any problem with the above link please feel free to contact me directly for a PDF copy. Kind regards,Andrea Cabrera ------------------------------ Andrea Cabrera, PhD Marine Evolution and Conservation (MarECon)Genomics Research in Ecology and Evolution in Nature (GREEN) Groningen Institute for Evolutionary Life Sciences Faculty of Science and Engineering University of GroningenNijenborgh 7 9747 AGGroningen The Netherlands Office phone: +31 50 363 2226 Mail address: PO Box 11103 9700 CC Groningen The Netherlands